Benzo[b]thiophene-2-carbonyl chloride

The physical properties of lead and mercury medicinal herbs are as follows:
Lead and mercury are often in the genus of gold and stone. Lead is heavy in quality but heavy in nature, gray and black in color, with a metallic luster, feels cold to the touch, its body is soft, can be developed into thin sheets, and its melting point is quite low. It melts into a liquid state at about 300 degrees. It is heated in fire and is easy to combine with other things. Mercury, commonly known as mercury, is the only liquid metal at room temperature. It is silver-white and has a flowing luster. It has a heavy texture. Although it is a liquid, it is difficult to adhere to other things. It is like a pearl rolling, and its volatility is strong. It can gradually dissipate in the air. The boiling point of mercury is also not high, and it can easily be turned into a gas when heated.
The qi of the medicinal pills formed by the two is often mentioned in alchemy in ancient times. Although its qi is invisible, it has the characteristics of lead and mercury. The gas has a sense of weight, although it is difficult to see its shape, it can be deposited in a low place like a mist, which seems to have a tendency to settle, which is the weight of lead. And the characteristics of mercury in the gas have a certain volatility, which persists in a closed space for a long time. If it is not properly contacted, it is easy to cause harm to people. Its smell is unique, although it is difficult to express, but alchemists can often detect it, mixed with the fishy smell of metal and the smell of variation in the refining process of medicinal pills. The energy of medicinal pills, in terms of physical properties, has both the dignified sedimentation characteristics of lead and the volatile flow of mercury. The combination of the two has become a unique existence in the ancient alchemy situation, which has been explored by many alchemists. However, its toxicity cannot be underestimated. Nowadays, people use scientific methods to clarify its nature, and no longer pursue it blindly as in ancient times.

Lead Dan, also known as trilead tetroxide ($Pb_3O_4 $), is a common chemical substance. Its chemical properties are quite rich and it has important uses in many fields. The following is your detailed description.
Lead Dan is oxidizing. If it reacts with hydrochloric acid, it will form lead chloride, chlorine gas and water. The chemical reaction equation is: $Pb_3O_4 + 8HCl = 3PbCl_2 + Cl_2 ↑ + 4H_2O $. In this reaction, the lead valence of lead Dan decreases, showing oxidizability, oxidizing chloride ions in hydrochloric acid to chlorine gas.
Lead Dan can also react with acids. In addition to hydrochloric acid, when reacting with nitric acid, lead Dan will be converted into lead nitrate and water due to the strong oxidation of nitric acid. The chemical reaction equation is: $Pb_3O_4 + 4HNO_3 = PbO_2 + 2Pb (NO_3) _2 + 2H_2O $. The lead dioxide generated by this reaction is a black solid, which is the characteristic product of the reaction between lead Dan and nitric acid.
Under heating conditions, lead Dan will decompose. When the temperature reaches a certain degree, $Pb_3O_4 $will decompose into lead oxide and oxygen. The reaction equation is: $2Pb_3O_4\ stackrel {\ Delta }{=\!=\!=} 6PbO + O_2 ↑ $. This reaction shows that lead Dan has poor thermal stability and will decompose to produce oxygen at higher temperatures.
Lead Dan is widely used in the paint industry. Because of its good hiding power and anti-corrosion properties, it is often used as an anti-rust pigment. When applied to the metal surface, a dense protective film can be formed to isolate oxygen and moisture, achieving the purpose of anti-rust. And the color of lead Dan is orange-red, which can give a unique color to the paint.
In the field of traditional Chinese medicine, lead Dan also has a place. According to ancient records, lead Dan has the functions of detoxification, muscle growth, falling phlegm and so on. However, it should be noted that lead Dan contains lead elements, which are toxic. When using it, you must follow the doctor's instructions and strictly control the dosage and usage to avoid lead poisoning.
To sum up, the chemical properties of lead Dan make it valuable in both industrial and pharmaceutical fields. However, during use, due to the toxicity of lead, appropriate protective measures must be taken to ensure personal safety and the environment from pollution.

"Tiangong Kaiwu" says: Saltpeter and sulfur are both essential for making gunpowder. Saltpeter, also known as flame nitrate, potassium saltpeter, etc., is a common method of preparation, including frying and refining with earth nitrate. The ancient method is to take more nitrate-containing soil and drizzle it with water to obtain nitrate water. After evaporation and crystallization, saltpeter can be obtained.
The preparation of sulfur is commonly obtained from calcining pyrite. First, the pyrite is broken up, placed in a kiln, and calcined by fire. The pyrite decomposes, escapes sulfur gas, and coagulates when cold, which is sulfur.
To make potassium chlorite, potassium chlorate is often used to co-heat with a reducing agent. In a suitable vessel, add potassium chlorate, add an appropriate amount of reducing agent, such as carbon powder, and slowly heat. Potassium chlorate decomposes by heat, and part of the oxygen combines with the reducing agent, and the rest produces potassium chlorite.
There is also a method of reacting potassium hydroxide with chlorine dioxide. The chlorine dioxide gas is slowly passed into the potassium hydroxide solution, and after the reaction, the potassium chlorite solution can be obtained. After evaporation, crystallization and other processes, potassium chlorite is also obtained.
To make sodium chlorite, it is common to react with hydrogen peroxide and sodium hydroxide solution with chlorine dioxide. In the reaction kettle, the solution of sodium hydroxide is filled, chlorine dioxide gas is slowly introduced, and hydrogen peroxide is added dropwise to control the reaction conditions. A sodium chlorite solution can be generated, which is evaporated and concentrated, crystallized and dried to obtain sodium chlorite.
Or react with sodium chlorate with sulfur dioxide and hydrogen peroxide. Dissolve sodium chlorate into a solution, pass sulfur dioxide gas, add an appropriate amount of hydrogen peroxide, and through a series of reactions, sodium chlorite can also be obtained. This method is a common method for preparing potassium chlorite and sodium chlorite.

"Tiangong Kaiwu" states that arsenic is the seedling of tin, and its growth must be caused by lead. Lead and stone gas go out of the cave, and are first mined like silver ingots, which are calcined through fire. Lead forms the bottom of the sand, and the sand is formed on the sand. The nature of arsenic is very poisonous, and it is obtained because of tin, so the name is tin.
As for the use of arsenic, it has been recorded in various places. In medicine, although arsenic is highly poisonous, it can be processed and used with precise dosage, and it can also be used as medicine to treat diseases. For example, for the treatment of cold phlegm and asthma, there are those who use arsenic combined with light tempeh as pills, which can be used in small amounts to remove phlegm and calm asthma.
In alchemy, it is also involved. The ancients made alchemy for longevity, often using all kinds of gold stones as materials, and arsenic was occasionally among them, thinking that they could refine miraculous medicinal pills, but most of them were poisoned and died due to excessive doses.
In agriculture, arsenic can be used to make insecticides. In the past, farmers used it to prevent pests and ensure the safety of crops. However, they should also be careful to use it, so as not to hurt crops and pollute soil and water sources.
In the field of metallurgy, arsenic is related to metal smelting. It is used in the refining of certain metal ores, or plays an auxiliary role, helping craftsmen extract pure metals.
Although arsenic has various uses, it is extremely toxic. It should be used with caution. If it is slightly wrong, it will endanger life. It is necessary to clarify its nature and use it in a scientific manner in order to avoid harm and profit.

"Tiangong Kaiwu" is a comprehensive work on agricultural and handicraft production in ancient our country. Sulfur [b] Arsenic genus, among which realgar, its storage conditions are quite critical.
Realgar, warm in nature, toxic, its chemical composition is arsenic sulfide. During storage, the first environment is dry. Because it is afraid of moisture, if it is in a humid place, it is easy to react with water vapor, causing changes in ingredients, affecting its quality and utility. Therefore, it should be stored in a dry and well-ventilated place, away from water sources and damp corners.
Furthermore, it needs to be stored away from light. Realgar is easy to decompose when exposed to light, and its active ingredients will be damaged by long-term light. It is advisable to keep it in a dark place or in an opaque container to avoid the harm of light.
And keep away from fire and heat sources. Realgar encounters hot topics and open flames, not only its own chemical properties will change, but it may also cause dangerous conditions such as combustion and even explosion, threatening the safety of storage places.
In addition, because of its toxicity, storage places should be properly managed to avoid mixing with food, medicine, etc., to prevent accidental ingestion or misuse, causing poisoning to humans and animals. Special areas should be set up and clearly marked to remind everyone to pay attention. < Br >
The storage of realgar requires conditions such as dryness, protection from light, fireproof heat, and anti-mixing to ensure its quality and safety, so that it can play its due role in the fields of medicine, industry, and so on.